I thought Robertson (the square hole screw heads) was more of a Canada thing?

Yes, my go to reference for construction, Holmes on Homes, says NEVER have bare untreated wood touching cement. It can absorb water from the cement.

You also have to consider the risk of basement leakage. Cracked foundation wall leaking, or rain/melt water buildup leaking in, may damage the bottom of your walls. Is this a risk? How good is the foundation drainage? Would you notice?

And, in much older houses, the concrete basement floor may not be particularly level. A raised wood subfloor allows you to level things so you can use tiles or carpet. But you may have a central floor drain, you may never notice if there's a water seepage until mold shows up, etc. Basement floods do more damage if you have to replace a raised floor. (I saw a Holmes episode where he used a floor leveler compound, like a very wet cement that leveled like water but hardened - to get rid of excessive slope. Don't block the drain. )